Depending on the placement of your tunnel, you may need to clean your tunnel plastic every so often. This is pretty simple but will require a bit of "elbow grease” if you are removing sap, dirt, or algae.
However, there are a couple of do’s and don’ts when it comes to choosing a method of cleaning.
Do not use bleach or anything abrasive on the tunnel plastic.
Bleach and many abrasives are simply too strong for the plastic and may deteriorate it over time. Also, they are usually toxic to the environment as well. Instead,
Use warm water with a mild detergent.
This method of cleaning is best applied with a soft-bristled brush or a telescoping flow-through brush and on a warm sunny.